This is malaria country. The prophylactics doxycycline and larium have unpleasant side effects (particularly larium) and only give 90% protection. The prophylactic malleron has no side effects but costs US$10 per tablet. Those who stay for long periods at Pemba do not use any prophylactics. The symptoms of malaria resemble flu: aching joints, a headache between the eyes, runny tummy, sensitivity to bright light, and a need to lie down all day (but often little or no temperature). Pemba residents are divided on what is the proper treatment.
However there is general consensus as regards coartem (contains artimesan) as the ultimate cure (recommended for body weights up to 75kg and, as yet, not FDA approved in USA where quinine injections must still be used). If malaria is suspected, but not severe, one should try taking a heavy dose of doxycycline (2 tablets 3 times a day with meals). Delay with treatment can be fatal. And remember: WHEN VISITING A CITY DOCTOR BACK HOME EMPHASISE THAT YOU HAVE BEEN IN A MALARIA AREA - IF HE SAYS YOU ARE FINE GET A SECOND OPINION - HE MAY NEVER HAVE SEEN A CASE OF MALARIA IN HIS LIFE BEFORE. There has been at least one death due to incorrect treatment by a city doctor. If you have been in a malaria area and are feeling seriously ill, treat yourself for malaria regardless of medical opinion to the contrary. The incubation period is a minimum of 7 days, but symptoms may not appear until about 2 weeks after being infected. Men, on average, seem to have greater natural immunity than women.
It is safest to visit in the dry season (May to October).
The best prophylactic is lots of mosquito repellent and long garments at dawn and sunset. You cannot get malaria unless the mosquito has already sucked blood from some other person who has malaria. Residing away from local people who may have malaria is recommended. Public toilets are an ultra high-risk zone. It is safer to use the bushes.
Of the 4 species of malaria parasites Pemba hosts two:
1) Plasmodium Falciparum which is responsible for the most serious form of the disease and the majority of deaths. It is also the one that if not properly treated is most like to become cerebral malaria (involvement of the brain capillaries), but any type of malaria can become cerebral;
2) Plasmodium Vivax which can remain in the body and reoccur at intervals. Note that once in the body all malaria is carried by the circulatory system to the liver, from where it leaves the liver to invade the red blood cells.
For more info see articles by the late Dr David le Sueur and Dr Lucille Blumberg:
DDT, banned worldwide for agricultural use, is now back in fashion for fighting malaria. It is the only poison that has proved effective against mosquitoes (Time Magazine 26 July 2004 at page 50). Pemba City Council regularly sends staff out to dust the interior of houses. DDT remains banned for agricultural use.
"Soft" landmines: The local habit of using the beach as a toilet has not completely died out, despite legislation, so watch out for soft landmines when strolling east along Wimbi. Municipal toilets were erected but stand disused (the toilet bowls have been stolen). One wonders why the authorities have not had the vision to install open air public floor level toilets, as has been done in Tanzania.
Watch out for coconut palm trees. A falling coconut can spoil a good holiday.